Coherent 420 nm laser beam generated by four-wave mixing in Rb vapor with a single continuous-wave laser

Liu Hao^{1, 2}, Yuan Jin-Peng^{1, 2, †}, Wang Li-Rong^{1, 2, ‡}, Xiao Lian-Tuan^{1, 2}, Jia Suo-Tang^{1, 2}

(a) Knife-edge measurements of the generated CBL beam and the pump beam at the chopper position. (b) Spectrum of the output beam measured by a narrow range grating spectrometer. The inset presents the CBL spatial profile.